How do I do that?
I tried adding a FB application ID/secret to the ACP, and it immediately enabled FB login/registration. I looked for an option to enable/disable FB registration, but couldn't find it.
I'd prefer not to designate FB users as admins because those IDs get leaked through the OG tags so anyone parsing the source can find the admins' FB accounts. So instead if I can designate a FB app as admin, then within FB it's easy to add admins to the app.